OMAP: DSS2: VENC: make 20ms venc bug-fix sleep optional

There's a 20ms sleep after VENC reset. It's unknown what bug this
circumvents and on what platforms. Add a Kconfig option to disable the
sleep.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/venc.c b/drivers/video/omap2/dss/venc.c
index 3269301..d5d4c5a 100644
--- a/drivers/video/omap2/dss/venc.c
+++ b/drivers/video/omap2/dss/venc.c
@@ -373,8 +373,11 @@
 		}
 	}
 
+#ifdef CONFIG_OMAP2_DSS_SLEEP_AFTER_VENC_RESET
 	/* the magical sleep that makes things work */
+	/* XXX more info? What bug this circumvents? */
 	msleep(20);
+#endif
 }
 
 static void venc_enable_clocks(int enable)